1. Field of the Invention
The present invention relates to the percutaneous treatment of vessels by an apparatus and method wherein the apparatus is delivered via catheter and comprises a surgical graft which is fixated in a vessel by means of a chemical or mechanical hardening-filler material system.
2. General Background
Previous methods of treating aortic aneurysms include treatment via surgical procedure in which an incision is made in the abdomen or chest of the patient, the diseased area is cleaned by the surgeon and an artificial graft is sutured in place. This highly invasive procedure usually results in long hospital stays and lengthy recoveries. Further, mortality and morbidity complications often result as a consequence of this surgical procedure.
Other percutaneous methods have been attempted, such as are disclosed in U.S. Pat. No. 4,577,631 (utilizing occlusion catheters with pressure sensitive adhesives), U.S. Pat. No. 4,740,207 (self-expanding stent-type materials) and U.S. Pat. Nos. 4,271,839, 4,776,337 and 4,762,132 (other stent derived devices).
There still exists a need, however, for a simple method of repairing a vessel with an intravascular graft which allows normal tissue ingrowth to occur at the repair site. There exists a specific need for a percutaneous approach in which a catheter could be loaded with a surgical graft that can be fixated in a vessel such as the aorta.
The present invention provides devices for repairing aortic aneurysms and the like. The intraluminal graft of the present invention in one embodiment comprises a flexible linear or bifurcated tubular sleeve delivered to a repair site in a body by suitable means such as a catheter. The sleeve is suitably made of woven or cast material, and has peripheral conduits or tubes at each end. Each conduit has at least a single port that is connected to an elongated introduction means associated with the catheter delivery means. The introduction means may be attached to the outer surface of the sleeve. The collapsed sleeve may be made rigid and circular by the introduction through the introduction means of a chemical or mechanical hardening means.
The chemical hardening means may be a polymeric material introduced through the introduction means through an external source, such as a catheter or syringe. Alternatively, the mechanical hardening means may comprise a single wire or multiple wires inserted into the conduits to support the ends, or any portion of the sleeve. The wires are not attached to the sleeve but reside in the conduits to provide a constant spring tension. The wires may be of any suitable material which retains its tension, such as spring wire or memory wire.
The introduction means may be detached from the sleeve after introduction of the chemical or mechanical hardening means.
The sleeve may alternatively be associated with a fixation means comprising either a series of cylindrical tubules or an enclosure which fits over the sleeve, with a hardening-filler system enclosed therein. The hardening-filler system includes an activatable hardening material which may be provided in the form of microspheres that upon external agitation may be disrupted, allowing the contents to react together and form a hardened material that fills the tubules or enclosure, thereby expanding and rigidifying the fixation means, and fixing the sleeve in place in the site of repair. Polymeric materials which are activatable include thioisocyanates, aldehydes, isocyanates, divinyl compounds, epoxides or acrylates. In addition to the aforementioned, photoactivatable crosslinkable groups as succinimidyl azido salicylate, succinimidyl-azidobenzoate, succinimidyl dithio acetate, azidoiodobenzene, fluoro nitrophenylazide, salicylate azides, benzophenone-maleimide, and the like may be used as photoactivatable crosslinking reagents. The material may also consist of a thin coating which can be activated by external forces such as laser, radio frequency, ultrasound or the like, with the same hardening result taking place. These materials would allow for normal tissue ingrowth to take place.